Transient short circuit currents and fluxes expressions of induction machines

In this paper, the expressions of transient currents and fluxes of an induction machine have been deduced in the case of a three phase short circuit of the supply network. Initial conditions assume that the machine is operating in no-load mode. In order to simplify the problem, the rotor speed is assumed to remain constantly at synchronous speed all over the time interval of interest. The analysis is based on the spatial phasor machine model and on the use of the Laplace transform. The short circuit state is thought to be produced by a superposition between regular and reversed supplies. Finally, the natural components and their characteristic parameters have been presented. Conclusions regarding the nature and the duration of the transient operation have been drawn.